1. Field of the Invention
The present invention relates to an image forming apparatus and an image forming method.
2. Description of the Related Art
In recent years, an image forming apparatus, such as a copier, a facsimile machine, or a printer, and an image forming method have been proposed which adjust image process conditions, such as a transfer current, according to an image area ratio to form a high-quality image (for example, see Japanese Patent Application Laid-open No. 2001-331005, Japanese Patent Application Laid-open No. 2009-168906, and Japanese Patent Application Laid-open No. 2004-29514). In addition, for example, image forming apparatuses have been proposed which adjust the image process conditions according to various conditions (for example, see Japanese Patent Application Laid-open No. 2001-331005, Japanese Patent Application Laid-open No. 2009-168906, Japanese Patent Application Laid-open No. 2004-29514, Japanese Patent Application Laid-open No. 5-273874, Japanese Patent Application Laid-open No. 9-134045, Japanese Patent Application Laid-open No. 2006-98473, and Japanese Patent Application Laid-open No. 10-254258).
However, as a result of examination, the inventors found that in some cases, with a technique for adjusting the image process conditions, such as a transfer current, according to the image area ratio on the basis of the pattern of an image to be formed, for example, on the basis of whether the image was a solid image or a linear image, image quality became unstable. It is considered that an unstable image quality is caused by a variation in the amount of toner forming an image depending on whether the image is a solid image or a linear image.